diff --git a/custom_components/nestquest/children.py b/custom_components/nestquest/children.py
index 44e2007..c0b6790 100644
--- a/custom_components/nestquest/children.py
+++ b/custom_components/nestquest/children.py
@@ -74,16 +74,25 @@ def _validate_sort_order(value: object) -> int:
 
 
 async def _warn_on_duplicate_name(
-    database: NestQuestDatabase, display_name: str
+    database: NestQuestDatabase,
+    display_name: str,
+    *,
+    exclude_child_id: int | None = None,
 ) -> None:
     """Log a warning when ``display_name`` duplicates an existing child.
 
     Case-insensitive and whitespace-normalised on both sides.  The
     duplicate is still allowed — this only makes it visible; the log
     line names both rows so an accidental double-add can be found.
+    ``exclude_child_id`` removes the child being edited from the scan,
+    so an edit only warns when the result collides with a DIFFERENT
+    child's name — including case-only edits, where the self-comparison
+    would otherwise hide a real duplicate.
     """
     lowered = display_name.casefold()
     for child in await ChildrenDao(database).list_all():
+        if exclude_child_id is not None and child.id == exclude_child_id:
+            continue
         if child.display_name.strip().casefold() == lowered:
             LOGGER.warning(
                 "Child display name %r duplicates existing child %d "
@@ -142,9 +151,10 @@ async def edit_child(
     field raises: the DAO's update writes only provided fields and
     cannot express NULL, so a silent no-op would mask the caller's
     intent (see the module docstring).  A provided display name is
-    validated like create's and, when it duplicates a DIFFERENT child,
-    still allowed with a warning.  Raises ValueError when the child
-    does not exist.
+    validated like create's; the duplicate scan excludes only the child
+    being edited, so a case-only edit colliding with another child's
+    normalised name still warns.  Raises ValueError when the child does
+    not exist.
     """
     dao = ChildrenDao(database)
     existing = await dao.get(child_id)
@@ -154,8 +164,7 @@ async def edit_child(
     if display_name is not _UNSET:
         name = _validate_text(display_name, "display_name", required=True)
         assert name is not None
-        if name.casefold() != existing.display_name.strip().casefold():
-            await _warn_on_duplicate_name(database, name)
+        await _warn_on_duplicate_name(database, name, exclude_child_id=child_id)
         updates["display_name"] = name
     if colour is not _UNSET:
         value = _validate_text(colour, "colour")
diff --git a/tests/test_children_registry.py b/tests/test_children_registry.py
index d88209d..3aa874d 100644
--- a/tests/test_children_registry.py
+++ b/tests/test_children_registry.py
@@ -291,21 +291,63 @@ def test_edit_child_rename_to_duplicate_warns_but_different_name_not(
         # Renaming Bo onto Ada's name warns (different child's name).
         edited = await edit_child(database, bo.id, display_name="ada")
         assert edited.display_name == "ada"
-        assert any(
-            "duplicates existing child" in r.getMessage()
-            for r in caplog.records
-        )
+        warnings = [
+            r for r in caplog.records if "duplicates existing child" in r.getMessage()
+        ]
+        assert len(warnings) == 1
+        assert "Ada" in warnings[0].getMessage()
+        return edited
+
+    _with_db(tmp_path, "edit-rename-duplicate.db")(_body)
+
+
+def test_edit_child_rename_to_own_name_casing_alone_warns_not(
+    tmp_path, caplog
+) -> None:
+    """Renaming a child to their own name (casing aside) is not a
+    duplicate when NO OTHER child carries the normalised name."""
+    async def _body(database):
+        ada = await create_child(database, "Ada")
         caplog.clear()
-        # Renaming a child to their own name (casing aside) is not a
-        # duplicate: no warning.
-        await edit_child(database, ada.id, display_name="ADA")
+        edited = await edit_child(database, ada.id, display_name="ADA")
+        assert edited.display_name == "ADA"
         assert not any(
             "duplicates existing child" in r.getMessage()
             for r in caplog.records
         )
+        return edited
+
+    _with_db(tmp_path, "edit-rename-self.db")(_body)
+
+
+def test_edit_child_case_only_edit_colliding_with_other_child_warns(
+    tmp_path, caplog
+) -> None:
+    """A case-only edit must not hide a real duplicate: with two Ada
+    profiles already present, editing either one's name to another
+    casing still warns (the scan excludes only the edited child)."""
+    async def _body(database):
+        first = await create_child(database, "Ada")
+        await create_child(database, "ada")
+        caplog.clear()
+        edited = await edit_child(database, first.id, display_name="ADA")
+        assert edited.display_name == "ADA"
+        warnings = [
+            r for r in caplog.records if "duplicates existing child" in r.getMessage()
+        ]
+        assert len(warnings) == 1
+        # Editing the name to a value that STAYS duplicated (no change,
+        # other child still carries it) warns too: the scan is on the
+        # resulting state, not on whether the word moved.
+        caplog.clear()
+        await edit_child(database, first.id, display_name=" ada ")
+        warnings = [
+            r for r in caplog.records if "duplicates existing child" in r.getMessage()
+        ]
+        assert len(warnings) == 1
         return None
 
-    _with_db(tmp_path, "edit-rename-duplicate.db")(_body)
+    _with_db(tmp_path, "edit-case-only-duplicate.db")(_body)
 
 
 # ---------------------------------------------------------------------------